Posttreatment of Effluent from Coke-Plant Wastewater Treatment System in Sequencing Batch Reactors

Removal of ammonia nitrogen in wastewater by microwave radiation: A pilot-scale study

“…In the past years, great efforts have been devoted to the removal of ammonia nitrogen from wastewater. Traditional methods for the removal of high concentration of ammonia nitrogen include biological systems [4], chemical precipitation [5], supercritical water oxidation [6,7], steam-stripping [8,9] and so on. The ammonia concentration after biological treatment is still high because the high concentration of ammonia leads to the low ratio of C/N [10].…”

Determination of ammonia removal from aqueous solution and volumetric mass transfer coefficient by microwave-assisted air stripping

“…Industrial wastewaters, such as coke plant, tannery, textile, landfill leachate, and fertilizer wastewaters, contain ammonia in high concentration (Lin et al 2009a;Yu et al 1997;Tchobanoglous and Burton 1991). Since the presence of even small amounts of ammonia has serious negative effects on ecology and human health and it can be used as a raw material, the importance of researches on ammonia recovery increases.…”

“…The recovery or/and removal of ammonia with low concentration and its compounds from wastewaters can be achieved by biological, physical, and chemical processes (Lin et al 2009a, b) or by a combination of these processes, such as adsorption, chemical precipitation, membrane filtration, reverse osmosis, ion exchange, air stripping, breakpoint chlorination, and biological nitrification (Lin et al 2009a). The recovery of industrial wastewaters by biological systems (Yu et al 1997), chemical precipitation (Uludag-Demirer et al 2005), supercritical water oxidation (Bermejo et al 2008;Segond et al 2002), and steam stripping (Ghose 2002;Yang et al 1999) is not satisfied due to the following disadvantages: (1) Biological processes are usually difficult to treat ammonia containing wastewaters due to their toxic nature and the certain C/N ratio requirement (Qian et al 1994;Lin et al 2009b), (2) chemical precipitation needs additional reagents leading to the formation of the new pollutants to the water sources (Uludag-Demirer et al 2005), (3) supercritical water oxidation requires high temperatures and pressures (Bermejo et al 2008), and (4) steam-stripping method uses a large stripping tower which consumes a large amount of energy, and ammonia concentration in effluent is often very high (Yang et al 1999). …”

Study on treatment of coking wastewater by biofilm reactors combined with zero-valent iron process

“…However, due to a certain number of refractory and inhibitory pollutants in coking wastewater, COD and NH 3 -N are poorly removed by the conventional activated sludge process. In China, anoxic-oxic (A-O), anaerobic-anoxic-oxic (A 1 -A 2 -O) and sequencing batch reactor (SBR) processes have been extensively investigated for coking wastewater treatment [13][14][15]. Unfortunately, these aforementioned processes are not efficient enough in practice to meet the National Discharge Standard of China ( GB8978-1996).…”